Do you know what atorvastatin is? How about esomeprazole? Olanzapine? Valsartan? Lansoprazole? Most people don’t recognize these drug names, even though they are among the bestselling drugs of all time. But how many do you recognize from this list: Lipitor, Nexium, Zyprexa, Diovan, Prevacid? Unless you’re a doctor, you probably recognized many more from the second list, which are simply the trademarked brand names of the first.

These drugs are hugely popular and represent billions of dollars of income for the companies that produce them. Lipitor grossed several billion dollars for Pfizer in 2006 alone. With the potential for so much income from a blockbuster drug, pharmaceutical companies spend millions developing their drugs and millions more marketing them. While many of these drugs are very effective at treating and preventing disease, a drug company’s primary motivation is to earn profits for its shareholders. Thus, even though there’s little evidence suggesting that Lipitor is any better than simvastatin, a much cheaper generic drug, it’s in Pfizer’s interest to steer patients to ask for Lipitor—and to get doctors to prescribe it. The evidence suggests they’re succeeding.

Helen Jaques is a British science journalist and an active presence on Twitter. She points to an Australian study published this month in PLoS Medicine. Australian doctors, the researchers found, are courted by the drug industry to the tune of $900,000 per week. The primary means of influence are “education events” for health professionals, often held in luxurious restaurants or hotels.

Jaques notes previous studies that suggest drug company–sponsored events do indeed affect doctors’ prescription behavior. In 91 percent of the cases in the Australian study, the sponsoring drug companies had a say in what topics were covered in the events. This marketing pays off big for the drug companies, as physicians appear significantly more likely to prescribe a drug if they attended an industry-sponsored education event than if they did not. All evidence suggests that the situation is no better in the US and Britain: Disclosure laws in those countries are less strict than in Australia, hinting that drug companies’ reach may be even stronger in the former than the latter.

The problem of drug company influence is compounded by media reporting of drug trials, Jaques says in an earlier post. Two-thirds of news articles on drug trials favor the brand name of the drug rather than the generic name, and more than 40 percent fail to report when a drug company finances a clinical study.

As Jake Young, a medical student who is also pursuing a PhD in behavioral neuroscience, pointed out on his blog Pure Pedantry, the PLOS Medicine study shows that the drug trials themselves, required by the FDA for drug approval, are also subject to industry bias. Clinical trials for drugs are sponsored by the companies developing the drugs. Unsurprisingly, when such trials show results that don’t favor a sponsor’s new drug, the findings are significantly less likely to be published. This means doctors are more likely to see evidence in research journals that favors the industry—and the new drugs that bring huge profits—whether or not they attend industry events or are swayed by gifts from sales representatives.

But eliminating industry bias isn’t a simple problem. If the pharmaceutical industry couldn’t pay doctors to assess their products in trials, it’s likely that new drug approvals would slow to a crawl. The FDA might sponsor its own clinical trials, as one researcher in the Australian study suggests, but Young notes that it barely has the resources to assess the effectiveness of industry-sponsored trials, let alone sponsor its own. And wouldn’t a government-run trial program introduce its own set of biases?

Clinical pharmacist Jennifer Gibson argues that if doctors were required to disclose all sources of industry funding, many doctors would simply stop doing research. Think of it this way—would you want your entire income published for anyone to scrutinize?

So while the influence of industry on research and medicine is clear and profound, it’s less clear what exactly should be done to make sure that influence doesn’t taint the research or treatments. As the debate continues, look for more discussion of these issues on ResearchBlogging.org.